GB2225434A - Measuring shear stress and strain characteristics of adhesives - Google Patents
Measuring shear stress and strain characteristics of adhesives Download PDFInfo
- Publication number
- GB2225434A GB2225434A GB8926050A GB8926050A GB2225434A GB 2225434 A GB2225434 A GB 2225434A GB 8926050 A GB8926050 A GB 8926050A GB 8926050 A GB8926050 A GB 8926050A GB 2225434 A GB2225434 A GB 2225434A
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- Prior art keywords
- shear
- specimen
- iosipescu
- measuring
- adhesive
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/24—Investigating strength properties of solid materials by application of mechanical stress by applying steady shearing forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N19/00—Investigating materials by mechanical methods
- G01N19/04—Measuring adhesive force between materials, e.g. of sealing tape, of coating
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- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
In an apparatus and method of measuring the stress and strain characteristics of adhesives under uniform shear conditions, an losipescu sample (10) is used, in which at the notched shear line, the sample is joined by the adhesive to be tested. Pure shear is applied to the sample at the bond line and the distortion of the adhesive bond is measured. The apparatus (20) is attached to the specimen (10) by clamp means (30). The apparatus (20) comprises a fork means (22) and means (21) to transmit the displacement of the two parts of specimen (10) to the fork means (22) and means to measure the displacement, for example strain gauges (24), attached to a Wheatstone bridge circuit. The specimen (10) with apparatus (20) attached is placed into a tensile testing machine having specially adapted grips to receive the sample and apply shear to the adhesive bond line.
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Description
n. r'. ? 5 43 4 i_ I- -- - 1 AN APPARATUS FOR MEASURING SHEAR STRESS AND
STRAIN CHARACTERISTICS OF ADHESIVES This invention relates to a novel apparatus and method for measuring the stress and strain characteristics of adhesives under uniform shear conditions. The invention makes use of an Iosipescu sample wherein the adhesive to be tested is placed at the shear line of the sample as a join.
Recently significant developments have resulted in new adhesives and their use in adhesive bonding so that adhesive bonding is now widely used as a joining method for critical structural components, especially in aerospace applications.
To achieve the required reliability and safety margins, designers need data on the shear stress-strain behaviour of adhesives, particularly on properties such as shear modulus and elastic and plastic strain to failure. Such data is not easily obtained, partly because of the difficulties in measuring strain in a bond line which may be only 0.1 mm in thickness. Although a number of test configurations are in existence all have some disadvantages, ranging from cost and problems in specimen preparation to a questionable shear field in the region of interest.
Prior-art methods of testing the characteristics of adhesives include the "thick-adherend lap shear-type" method which is fully disclosed in "Stress analysis concepts for adhesive bonding of aircraft primary structure" R.B. KRIEGER, from the International Conference on Structural Adhesives in Engineering, Bristol, UK, 1986, p. 1. The method uses essentially a lap shear specImen constructed with thick adherends to minimize shear stress non-uniformity. To measure shear distortion of the adhesive bond linetwo sensors (ie LVDT coils) are used for which separate modules provide power excitation, signal averaging and recording. Also, since the adhesive shear stress is not entirely uniform across the test area, there are some doubts as to whether a maxiumum distortion of-adhesive layer is obtained, and thus measured, for a given shear stress as a result of inherent adherends bending.
j The ASTM method (Designation: E229-70 (Reapproved 1981)) measures the pure shear of adhesives by applying torsional shear forces to the adhesive through a circular specimen which produces a uniform stress distribution. The torsional shear forces are applied by a torsional shear jig without inducing bending, peeling, or transverse shear stresses in the bond line. The shear strain is measured with an ASTM Class A or Class B-1 extensometer, or alternatively an optical lever system is used. However, even though this method is reasonably accurate and gives direct results, specimen preparation is very time consuming and costly.
A much simpler method involves using strain gauges directly on the specimen per se, but this method is also costly, since the gauge, once attached to the specimen, can be used only once, since after use it is disposed of with the sample.
Therefore, in the light of the apparent problems with the prior art, the applicants have invented an apparatus which is reusable and inexpensive, and also simpler to use, producing more accurate and direct measurements of strain.
The present invention is predicated upon selection of the "Iosipescu" method (see N. Iosipescu, Journal of materials, Vol. 2, No. 3, 1967, p 537). The test was originally developed for measuring the shear characteristics of metals and has in more recent years been extensively studied in relation to testing fibre-reinforced composites.
These studies have amply demonstrated the uniformity of the shear stress across the sample. The Iosipescu method involves choosing a specimen which at the shear line, when a shearing force is applied thereto, exhibits shear in that direction only, thus giving a true value of shear.
The present invention adapts the Iosipescu method to measuring the shear characteristics of adhesives by dividing the normal Iosipescu specimen into two at the shear line and rejoining the two sections with the adhesive to be tested.
4 The invention provides an apparatus for measuring the extent of the shear distortion in adhesive bonds comprising means for applying a shear force to an Iosipescu-type specimen, having an adhesive bond line as the shear line and means for measuring the resultant distortion of the adhesive bond.
Preferably, the invention may provide an apparatus for measuring shear in adhesive bonds wherein the apparatus may comprise an elastic fork with two strips wherein said strips deflect as a result of a shearing force applied to the specimen, means for attaching said fork to an Iosipescu-type specimen having an adhesive bond line as the shear line and said strips having means to measure the strain attached thereto. more preferably, strain gauges may be attached to the elastic strips to measure the strain resulting from any shear force applied to the specimen. Further, the strain gauges may be attached to a Wheatstone bridge circuit to measure the strain. Circuit bridge excitation power, signal conditioning and recording may be provided by an existing internal circuitry of the tensile testing machine.
Preferably said means for applying a shear force to an Iosipescu-type specimen comprises a clamp means adapted to retain the Iosipescu-type specimen and a force applying means. The clamp means thus aids in retaining the sample in position and allows the shear force to be accurately applied to the adhesive bond line of the Iosipescu sample.
Preferably the clamp means comprises at least two clamps which are adapted to fit onto either side of the bond line of the Iosipescu-type specimen and further, each of the clamps may be connected to the force applying means. The force applying means is preferably a tensile testing machine and the clamps means may be adapted to fit into existing recesses of the tensile testing machine. 35 The invention further provides a method of measuring the shear distortion in adhesive bonds comprising the steps of:
1 (a) preparing an Iosipescu-type specimen having an adhesive bond line of the adhesive to be tested as the shear line; (b) applying a shear force to the Iosipescu-type 5 specimen on its bond line; and (c) measuring the resultant distortion of the adhesive bond.
The method of the invention generally uses the apparatus as previous described.
Preferably, the resultant distortion of the adhesive bond is measured by an elastic fork with two strips wherein said strips deflect as a result of a shearing force applied to the specimen, means for attaching said fork to an Iosipescu-type specimen having an adhesive bond line as the shear line and said strips having means to measure the strain attached thereto. more preferably, strain gauges may be attached to the elastic strips to measure the strain resulting from any shear force applied to the specimen. Further, the strain gauges may be attached to a Wheatstone bridge circuit to measure the strain. Circuit bridge excitation power, signal conditioning and recording may be provided by an existing internal circuitry of the tensile testing machine.
Preferably said shear force is applied to an Iosipescu-type specimen via a clamp means adaptE!d to retain the Iosipescu-type specimen and a force applying means. The clamp means thus aids in retaining the sample in position and allows the shear force to be accurately applied to the adhesive bond line of the Iosipescu sample.
Preferably the clamp means comprises at least two clamps which are adapted to fit onto either side of the bond line of the Iosipescu-type specimen and further, each of the clamps may be connected to the force applying means.
The force applying means is preferably a tensile testing machine and the clamps means may be adapted to fit into existing recesses of the tensile testing machine.
The nature of the invention will be more fully appreciated in the following preferred embodiment.
1 Figure 1 is an example of an Iosipescu-type specimen.
Figure la is an example of an adherend.
Figure 2a is an embodiment of the apparatus of the invention with reference to the specimen.
Figure 2b is an embodiment of the apparatus of the invention once a shearing force has been applied to the specimen.
Figure 3 is a schematic drawing of a displaced elastic strip.
Figure 4 is an embodiment of the apparatus of the invention attached to the specimen.
Figure 5 is an embodiment of the apparatus of the invention attached to the specimen in tension grips.
Figure 6 is an example of the calibration curve illustrating the relationship between Wheatstone bridge output (/jv) and Mikrokator displacement (mm).
Figure 7 is an example of a shear stress-strain curve of the expoxy-based film adhesive FM1000.
Figure 1 discloses a schematic drawing of an adhesively bonded Iosipescu-type specimen 10, in which two adherends 11 of the material to be joined are connected with adhesive 12 on the bond area (13 on Figure la).
Figure la discloses an adherend 11 wherein a is 450 to the bond area 13.
Figure 2a illustrates a preferred embodiment (expanded view)of apparatus 20 of the invention.
The embodiment discloses three parts; means 21 to transmit the relative displacement of the adherends to the elastic strips of a two prong elastic fork 22 with sensing devices 24 (preferably strain gauges) thereon wherein each prong fits into the means 21 for transmitting the relative displacement of the adherends and means 23 to support the elastic fork 22.
Figure 2b shows the apparatus (expanded view) in displacement mode. The adherends'll shear deflection is reproduced by the means 21 which transmits the relative displacement of the adherends to the elastic strips of the fork 22. Thus for a given individual displacement 1 (d) each strip of the fork 22 experiences an end applied moment (M A). As a result of the opposing applied moments, the elastic strips of the fork are subjected to bending giving rise to surface compressive and tensile strains (i.e. twoEand twoc+ respectively) away from the plane of inflection (x-x).
The means 23 is a slotted bar interference fitted onto the other end of the fork 22 and assists in balancing counteracting reactive moments (M R) of opposing direction.
Preferably, to each side of the two elastic strips of the fork a small uniaxial strain gauge is adhesively bonded (close to the sample end of the strips) and wired to form a Wheatstone bridge circuit. This forms the sensing means 24) as illustrated, from which the strain values are recorded.
The problem of determining the actual site of strain gauge attachment has been resolved by a combination of theoretical and experimental approaches. Theoretically, it could be shown that the magnitude of the surface compressive or tensile strain along the strip's free length and its dependence on that length can be derived from single beam theory. The illustration, (Figure 3) showing one elastic strip (side view), is analogous to a beam member constrained at both ends, for which it is known that the case is governed by d 4 y 0 dx 4 .....................
where y is displacement and x is distance along the beam from either constrained end. Also from Figure 3 y = 0 for X = 0 y = d for x = L and dy dx = 0 for X = 0 and x = L 1 where d is the total end displacement and L is the free length. Solving equation (i) with these conditions gives is 2 y = -- X L 2 3d 2x 1_ - 3L However, surface strain (tensile) is given by t 2R where t is beam thickness and 1 d 2 y R dX2 is the curvature at any point along the beam. using equation (ii) and solving gives Mt ............ (ii) Therefore 2x = --- 1_ - L 2 L................ (iii) which indicates that strain at the half-length of the beam (x = L/2, point of inflection) vanishes and increases along the beam reaching a maximum at either end (ie. x = 0 or 30 x = L) thus reducing equation (iii) to rn a x Mt - - - L 2 ................ (iv) Note also, from equation (iv), that for a given displacement (d) strain is increased by decreasing beam length (L).
From the above it is shown that if the strain gauges are to be usefully employed, their position should be close to an end of an appropriately short elastic strip. Their equally distant positions from the chosen end will also ensure that the circuit bridge is temperature compensated and that the magnitude of the compressive and/or tensile strains, seen by the strain gauges attached to these sites, are comparable.
The experimental part of this approach was concerned with implementing the above findings. This entails optimizing the strips' length and positioning the strain gauges so that the circuit bridge produced the largest output signal (ie. highest strain) for a minimal displacement with signal linearity over the entire measuring range.
Figure 4 illustrates a preferred embodiment of apparatus 20 shown to a specimen 10. The apparatus 20 is attached in this preferred embodiment with G-type clamps 30. A positioning device (not shown) can be used to align the apparatus symmetrically over the adhesive bond line.
Figure 5 illustrates a specimen 10 with an attached apparatus 20 in grips 40 suitable for tensile loading and adapted to fit into a tensile testing machine.
The specimen is kept in place by securing screws 41 being previously aligned by a positioning device (not shown) to ensure that the bond line is properly aligned. To this fixed arrangement the shearing force is applied in the direction of the arrows shown by the tensile testing machine. in practice, the specimen final dimensions correspond to the Iosipescu data set out in the journal article by N. Iosipescu. A preferred adherend may have the following dimensions (depending on the tensile strength testing machine and grips etc.), Figure 1A 1 = 50 mm t = 10 mm b = 20 mm a = 4 mm 12 mm 450 1 No lateral notches are considered necessary as suggested in the Iosipescu journal. Adherends can be reused several times by remachining after each test if they cannot be cleaned by simple chemical means. This remachining process by which a fraction of a millimetre is taken off the bonding surface and notch faces is considered acceptable since there is no evidence of permanent set due to repeated application of the loads reached during the testing of the adhesive.
is The bonding step is the most critical of the testing procedure. Adherends must be axially aligned before, during and after bonding to ensure bond line thickness uniformity and to allow the accurate measurement of the bond line thickness. The bonding pressure to the adherends must be accurate and constant while the adherends are being bonded. Ideally, a calibrated screw-operated spring clamp which encloses the specimen can be used to retain the specimen axially aligned and place a constant pressure to the specimen.
The bonding surface of the adherend is pretreated in a conventional way, for example, when epoxy film adhesives are being tested, the bonding surface of the aluminium adherend is first subjected to a standard surface pretreatment(i.e. vapour degrease and chromic acid etch). The cure is performed in a temperature controlled, air circulating oven. Specimens temperature near the bond line is monitored by a thermocouple inserted through the wall of the bonding assembly.
The bond line thickness must be measured in order to obtain meaningful and reliable shear data from the shear stress-strain curve. The selected technique involves measurement of the end-to-end distance of the adherend pair before and after bonding, thus giving the bond line thickness by difference. These measurements are performed by the use of a commercially available comparator equipped with a high resolution Mikrokator. Using the Mikrokator, reliable and reproducible bond line thickness measurements with an accuracy of 2.5 x 10-3mm can easily be achieved. In - 10 practice, handling of aluminium adherends should be minimized to maintain dimensional stability.
Prior to testing, the apparatus of the invention must be calibrated in order to determine the relationship between the displacement of the strips and the Wheatstone bridge output.
Thus the strips are displaced and the distance measured and the corresponding Wheatstone bridge output is recorded.
For calibration purposes the Wheatstone bridge was operated at 1.03 V supplied by a Strain Gauge Meter model RD-203, manufactured by Applied Measurements, Australia and the output read from a Keithley 177 uV, digital multimeter. The resulting calibration curve, representative of any part of shearometer's measuring range of about 0.5 mm, is shown in Fig. 6. The typical sensitivity is 2.3 uV/um.
The apparatus is then attached to the specimen as illustrated in Figure 4 and aligned onto the specimen to ensure that it lies symmetrically over the adhesive bond line.
The specimen with the apparatus attached thereto is then placed in the test grips suitable for tensile loading. once again the specimen is aligned to ensure that the bond line is in the line of shearing forces.
The specimen is now ready for shear testing.
During actual shear testing the adhesive bond is continuously deformed as one adherend is moved with respect to the other at a preselected speed. One half of the attached apparatus reproduces this movement and as it does so the Wheatstone bridge becomes unbalanced due to the change in resistance of a stretched strain gauge foil. The recorded bridge output voltage is, hence, taken as being equivalent to a combined strain on adhesive and adherends. The contribution of the adherends is-subtracted from above by evaluating their elastic deformation under identical test conditions using an identically shaped non-bonded specimen.
An example of the data and its reproducibility obtainable from this method is shown in Figure 7. This 1 - 11 gives the shear stress-strain curve of the epoxy-based film adhesive FM1000, which has been extensively used in the aircraft industry for many years, especially in such applications as helicopter rotor blades. From the initial, linear part of the curve the shear modulus can be determined: the rest of the curve provides information on the adhesive's elastic limit and strain to failure as well as the shear failure stress.
The application of the losipescu shear test as adapted for the determination of properties of structural adhesives under conditions of uniform shear has been described. This invention is an inexpensive, reusable and highly sensitive instrument that gives reproducible results. As a whole, it has been shown that the apparatus and method of using thereof enables determination of the complete adhesive stress-strain behaviour and thus evaluation of shear modulus, elastic and plastic strain to failure and the ultimate shear stress.
Claims (10)
1. An apparatus for measuring the extent of the shear distortion in adhesive bonds comprising:
(a) means for applying a shear force to an Iosipescu-type specimen, having an adhesive bond line as the shear line; and (b) means for measuring the resultant distortion of the adhesive bond.
2. The apparatus of claim 1, wherein said means for measuring the resultant distortion of the adhesive bond comprises:
(i) an elastic fork with two strips wherein said strips deflect as a result of a shearing force applied to the specimen and each strip each having attached thereto means for measuring the strain; and (ii) means for attaching said fork to the specimen.
3. The apparatus of claims 1 or 2, wherein said means for applying a shear force to an Iosipescu-type specimen comprises:
(i) a clamp means adapted to retain the Iosipescu-type specimen; and (ii) a force applying means.
4. The apparatus of claim 3, wherein said clamp means comprises at least two clamps which are adapted to fit onto either side of the bond line of the Iosipescu-type specimen and each of said clamps is connected to the force applying means.
5. Method of measuring the shear distortion in adhesive bonds comprising the steps of:
(a) preparing an Iosipescu-type specimen having an adhesive bond line of the adhesive to be tested as the shear line; (b) applying a shear force to the Iosipescu-type specimen on its bond line; and (c) measuring the resultant distortion of the adhesive bond.
6. The method of claim 5, wherein the resultant distortion of the adhesive bond is measured by:
(i) an elastic fork with two strips wherein said strips deflect as a result of a shearing force applied to the specimen and each strip each having attached thereto means for measuring the strain; and (ii) means for attaching said fork to the specimen.
7. The method of claims 5 or 6,wherein a shear force is applied to the Iosipescu-type specimen by:
(i) a clamp means adapted to retain the Iosipescu-type specimen; and (ii) a force applying means.
8. The method of claim 7, wherein said clamp means comprises at least two clamps which are adapted to fit onto either side of the bond line of the Iosipescu-type specimen and each of said clamps is connected to Ithe force applying means.
9. Shear distortion measuring apparatus substantially as herein described with reference to Figure 2B, Figure 4 or Figure 5 of the accompanying drawings.
10. A method of measuring the shear distortion of adhesive bonds substantially as described herein with reference to the accompanying drawings.
Rjt'ishei 1990 at. The Paten Cf-e 5 a- H Cc -1 H:,- H P. 4TF Furt.-,er 2, p ieci-.a-,, be -n Ken' Fi-- 21R1 Prin- tv Saies: Eranch. S C- C 7,-: n C
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPJ152688 | 1988-11-18 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8926050D0 GB8926050D0 (en) | 1990-01-10 |
| GB2225434A true GB2225434A (en) | 1990-05-30 |
Family
ID=3773515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8926050A Withdrawn GB2225434A (en) | 1988-11-18 | 1989-11-17 | Measuring shear stress and strain characteristics of adhesives |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US5033309A (en) |
| GB (1) | GB2225434A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0863028A2 (en) | 1997-03-07 | 1998-09-09 | Robert Bosch Gmbh | Method for detecting a deflated tire on a vehicle |
| GB2354334A (en) * | 1999-09-15 | 2001-03-21 | Praxair Technology Inc | Method of testing a bond interface |
| WO2009065378A3 (en) * | 2007-11-19 | 2009-07-16 | Fraunhofer Ges Forschung | Sample arrangement for testing a joint |
| CN103454161A (en) * | 2013-08-15 | 2013-12-18 | 西安理工大学 | Dynamic simple shear apparatus of servo cylinder-driven cubic articulated mechanism |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2733048B1 (en) * | 1995-04-12 | 1997-05-16 | Snecma | DEVICE FOR MEASURING DEFORMATIONS OF A TEST SUBJECT TO A SHEAR TEST |
| US5796007A (en) * | 1996-09-23 | 1998-08-18 | Data Instruments, Inc. | Differential pressure transducer |
| DE10042289A1 (en) * | 2000-08-29 | 2002-03-14 | Beiersdorf Ag | Measurement of viscoelastic properties of pressure-sensitive adhesives, especially for medical and technical adhesive tapes, comprises subjecting sample of adhesive to constant shear stress and determining shear produced over time |
| FI117028B (en) * | 2001-11-14 | 2006-05-15 | Paroc Group Oy Ab | Apparatus and method for determining the shear strength of mineral wool insulation material of a sandwich building element |
| US6776049B2 (en) | 2001-12-07 | 2004-08-17 | Alliant Techsystems Inc. | System and method for measuring stress at an interface |
| DE102004011099B3 (en) * | 2004-03-06 | 2005-12-08 | Robert Bosch Gmbh | Device for testing material properties with regard to tensile shear loads, in particular for testing adhesives |
| CN104677750B (en) * | 2015-02-02 | 2017-11-24 | 南京航空航天大学 | A kind of shear test apparatus and its operating method |
| CN106289595A (en) * | 2015-05-26 | 2017-01-04 | 鸿富锦精密工业（深圳）有限公司 | The force transducer of shearing force can be detected |
| CN107063853B (en) * | 2017-06-16 | 2023-08-11 | 哈尔滨工业大学 | Clamp for testing shear performance of V-shaped notch beam sample |
| CN113484165B (en) * | 2021-07-30 | 2024-04-09 | 中国航空工业集团公司济南特种结构研究所 | Efficient test method for shearing mechanical property of composite material |
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|---|---|---|---|---|
| US3802254A (en) * | 1972-10-30 | 1974-04-09 | Rohr Industries Inc | Shear modulus extensometer |
| US4010640A (en) * | 1975-10-16 | 1977-03-08 | American Cyanamid Company | Apparatus for measuring the stiffness characteristic of structural adhesives |
| US4010641A (en) * | 1975-10-16 | 1977-03-08 | American Cyanamid Company | Apparatus for measuring the stiffness characteristic of structural adhesives |
| US4346602A (en) * | 1980-10-21 | 1982-08-31 | The United States Of America As Represented By The Secretary Of The Army | Apparatus and method for measuring adhesive bond strength |
| GB2151798A (en) * | 1983-12-16 | 1985-07-24 | Schenck Ag Carl | Testing the shearing strength of jointed test pieces |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3184962A (en) * | 1962-07-13 | 1965-05-25 | Herman P Gay | Strain type transducers |
| US4041806A (en) * | 1976-10-18 | 1977-08-16 | The Goodyear Tire & Rubber Company | Testing cord-to-elastomer adhesion |
| SU855443A1 (en) * | 1979-07-05 | 1981-08-15 | Предприятие П/Я А-3607 | Specimen for determination of adhesion strength and method of manufacturing thereof |
| DE3712073A1 (en) * | 1987-04-09 | 1988-10-20 | Bayer Ag | METHOD AND DEVICE FOR MEASURING THE LIABILITY OF FIBERS IN FIBER REINFORCED PLASTICS |
-
1989
- 1989-11-16 US US07/437,090 patent/US5033309A/en not_active Expired - Fee Related
- 1989-11-17 GB GB8926050A patent/GB2225434A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3802254A (en) * | 1972-10-30 | 1974-04-09 | Rohr Industries Inc | Shear modulus extensometer |
| US4010640A (en) * | 1975-10-16 | 1977-03-08 | American Cyanamid Company | Apparatus for measuring the stiffness characteristic of structural adhesives |
| US4010641A (en) * | 1975-10-16 | 1977-03-08 | American Cyanamid Company | Apparatus for measuring the stiffness characteristic of structural adhesives |
| US4346602A (en) * | 1980-10-21 | 1982-08-31 | The United States Of America As Represented By The Secretary Of The Army | Apparatus and method for measuring adhesive bond strength |
| GB2151798A (en) * | 1983-12-16 | 1985-07-24 | Schenck Ag Carl | Testing the shearing strength of jointed test pieces |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0863028A2 (en) | 1997-03-07 | 1998-09-09 | Robert Bosch Gmbh | Method for detecting a deflated tire on a vehicle |
| GB2354334A (en) * | 1999-09-15 | 2001-03-21 | Praxair Technology Inc | Method of testing a bond interface |
| WO2009065378A3 (en) * | 2007-11-19 | 2009-07-16 | Fraunhofer Ges Forschung | Sample arrangement for testing a joint |
| CN103454161A (en) * | 2013-08-15 | 2013-12-18 | 西安理工大学 | Dynamic simple shear apparatus of servo cylinder-driven cubic articulated mechanism |
| CN103454161B (en) * | 2013-08-15 | 2015-06-24 | 西安理工大学 | Dynamic simple shear apparatus of servo cylinder-driven cubic articulated mechanism |
Also Published As
| Publication number | Publication date |
|---|---|
| US5033309A (en) | 1991-07-23 |
| GB8926050D0 (en) | 1990-01-10 |
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